wallmann



March 31, 1964 G. R. WALLMANN PUSH-FREE DOOR OPERATOR Filed Feb. 23, 1962 Fig. I

2 Sheets-Sheet 1 INVENTOR.

GEORGE R. WALLMANN BUCKHORN, CHEATHAM 8 BLORE ATTORNEYS March 31, 1964 R wALLMANN I 3,127,160

' PUSHFREE DOOR OPERATOR Filed Feb. 23, 1962 2 Sheets-Sheet 2 Fig. 7

59 8 so 59 1s 31 I0 IO 42 Fig. I0

Fig.1!

BUCKHORN, CHEATHAM 8 BLORE ATTORNEYS United States Patent 3,127,160 PUSH-FREE DUQR @PERATGR George R. Walhnann, R9. Box 526, Lake (Dswego, Greg. Filed Feb. 23, 1962, Ser. No. 175,929 17 Claims. (Cl. 263-63) My present invention comprises a swinging door construction of the power-opened type, and may be characterized as a semi-automatic construction since opening movements require continuous pressure against a pressure switch, as distinguishable from the automatic construction wherein a single touch of a pressure switch or the single blocking of a light beam to a photoelectric cell switch causes a complete opening and closing movement of the door.

A principal object of the present invention is to provide means for actuating a swinging door wherein continuous pressure on a pressure switch, such as a switch actuated by a push plate or panic bar mounted upon the door or a switch actuated by a tread panel mounted in the floor, is required to cause continuous opening of the door. The principal purpose of the present invention is to provide means whereby a person opening a door has to actually move, but not push, the door open, thus overcoming the psychological reaction of timid persons who fear that an automatic door might slam shut against them as they stepped through the door opening.

A further purpose of the present invention is to provide means of the foregoing character which will prevent the door from slamming shut against a person who, by reason of injury or distraction, may stop before he is safely beyond the area traversed by the swinging door.

A further object of the present invention is to provide a door construction of the foregoing character which is designed to prevent damage to the door or to its actuating mechanism in the event that the door should be blocked from swinging fully open or fully closed.

A further object of the present invention is to provide means of the foregoing character which is easily adjustable to vary the pressure holding a door in closed position, for example to increase the pressure materially in order to hold doors closed in an area subject to high winds, without requiring correspondingly greater force to open the door.

A further object of the present invention is to provide means of the foregoing character which, by simple modification, may be formed to apply to a single swinging door or to a pair of oppositely hinged swinging doors for simultaneous operation thereof, in which latter modification opening of either of the doors will operate both.

The foregoing objects and advantages of the present invention may be more readily understood by reference to the accompanying drawings, wherein:

FIG. 1 is a view in vertical section of a preferred form of the present invention in association with a single swinging door;

FIG. 2 is a vertical section taken substantially along line 22 of FIG. 1;

FIG. 3 is a vertical section taken substantially along line 3-3 of FIG. 1;

FIG. 4 is a vertical section taken substantially along line 4-4 of FIG. 1;

FIG. 5 is a horizontal section looking upward substantially from the plane of line 5-5 of FIG. 1;

FIG. 6 is a schematic wiring diagram showing the control means for the modification of FIG. 1;

FIG. 7 is a view similar to FIG. 1, partly broken away, and illustrating a modification of the device of FIG. 1 for adaptation of the invention to a pair of oppositely hinged swinging doors;

FIG. 8 is a vertical section taken substantially along line 8-8 of FIG. 7;

Patented Mar. 31, 1964 FIG. 9 is a horizontal section looking upward substantially from the plane of line 9 of FIG. 7;

FIG. 10 is a partial vertical section similar to FIG. 7, showing a further modification of the invention wherein fluid pressure actuated motive means are provided instead of the electric motive means of the prior modifications; and

FIG. 11 is a schematic view of a control circuit for the modification of FIG. 10.

In FIGS. 1 to 6, inclusive, the invention is illustrated as applied to a single swinging door hung at its right side in a door opening 11. A housing 12 is mounted above the door, comprising a longitudinal, horizontally disposed, inverted channel bar 13 welded to an end plate 14 at one end and a pivot bracket 15 at its other end, both the end plate and the pivot bracket being adapted to be secured to the door framing members such as by lag screws. The side flanges of the channel 13 mount decorative panels 16, the lower edges of which support piano hinges 17 hingedly securing a pair of lower decorative members 18 completing the housing. The members it? substantially meet along the longitudinal centerline of the lower surface of the housing just above the door, and are held in closed position by a plurality of clips 19 which may be removed to permit access to the interior of the housing.

The pivot bracket 15 supports a vertically disposed pivot member 22, the lower end of which projects heneath the housing and is provided with a plurality of flanges 23 adapted to embrace the upper corner of the door 16 and be suitably secured thereto. It is to be appreciated that a lower pivot member (not shown) is attached to the lower corner of the door and seated in a bearing socket in the floor. Crank means are afiixed to the upper end of the pivot member 22, comprising a crank disc 24 to which are affixed a pair of vertically disposed crank pins 25 equidistantly spaced on opposite sides of the centerline of the pivot and door, normally rearwardly of the pivot, at a spacing of about degrees. Rollers 26 are preferably mounted on the pins 25.

Guide means comprising a pair of angle bars 29 extend longitudinally within the channel 13 on opposite sides thereof and provide tracks for supporting wheels 30 on the opposite sides of a reciprocally guided carriage 331. Guide wheels 32 turning about vertical axes are mounted upon the carriage so as to engage the sidewalls of the channel 13. There are four Wheels 30 and four wheels 32 so spaced and arranged as to prevent binding of the carriage wlnle permitting free longitudinal movement thereof. A flange 33 depending from the middle of the carriage supports a spring-retainer pin 34 which holds one end of a helical spring 35 in position. The other end of the spring 35 is held in position by the protruding end of an elongated screw 36 which protrudes from a spring backing member 37 threaded to act as a follower nut and engaged on the threads of the screw 35. The member 37 is provided with an offset guide wheel $3 mounted for revolution about a horizontal axis and guided in a channel guide 39 fixed to a wall of the channel 13.

When the door is fully closed the parts are in the relative positions illustrated, in which the spring 35 is compressed and thrusts the carriage 31 toward the right so that the squared end thereof is thrust against the crank pins 25. The longitudinal center of this end of the carriage .is provided with a recess 41 enabling the end of the carriage to straddle the pivot member 22. The extent of compression of the spring 35 in this position of the parts depends upon the extent to which the backing member 37 has been screwed toward the pivot member 22. This may be varied by adjusting the position of a limit switch 42 engageable by the backing member 37 as it is moved away from a motor 43 which rotates the screw 36. The position of limit switch 42 is set by adjusting a pair of screws 44- which support it, and which are supported in suitable brackets mounted on the channel 13, The opposite limit of movement of the backing member 37 is controlled by a second limit switch 45 mounted in the channel 13.

The motor is under control of the control circuit, schematically illustrated in FIG. 6, which includes a pressure switch 47 mounted in the desired position such as beneath a tread plate (not shown) or behind a pushplate 48 mounted adjacent the opening edge of the door. The switch 47 is connected in the circuit by wires which are concealed within the door and pass upwardly into the housing through a bore traversing the pivot member 22. Pressing upon the switch 47 closes a circuit to a relay which completes the circuit to the reversible electric motor 43 through the closed limit switch 45. The motor is thereby caused to operate in a direction of rotation to cause the backing member 37 to relieve the compression of spring 35. The threads of the screw 36 are preferably fine so that the movement is relatively gradual, whereby a person walking at a steady pace feels the resistance of the spring 35 by reason of one of the cranks 25' causing the carriage .31 to follow the movement of the spring backing member. This movement can be continued until the door is fully opened, at which time the motor is arrested by the spring backing member opening the second limit switch 45. As long as pressure is maintained against the switch 47, the door will be held open, since the motor does not operate in either direction. As soon as pressure is relieved from the pressure plate, the relay 5% will move to close the circuit through the now closed first limit switch 42, whereupon the motor will operate in reverse to run the spring backing member back to its normal position of rest. This action compresses the spring 35 and causes the door to move toward closed position. The speed of return movement is limited by a dashpot device 51 fixed to the channel 13 and receiving a plunger 52 fixed to the flange 33. When the door reaches its fully closed position, the motor is arrested and the door is held in closed position by the carriage bearing against both crank pins 25 under a force depending upon the extent of compression of the spring 35.

FIGS. 7, 8 and 9 disclose the adaptation of the foregoing to a pair of oppositely hinged swinging doors '10. Each door will have associated therewith the cranks 25 and a carriage 31 arranged to be operated simultaneously but in reverse directions. The motor 43 in this instance comprises a double-end motor, one end of which drives the screw 36 as before, and the other end of which is coupled to an oppositely threaded screw 55 so that the spring backing members are moved simultaneously in opposite directions. Each pivot member 22 is provided with a sprocket 56 about which is trained an endless sprocket chain 57, the pair of sprocket chains terminating close together adjacent the motor 43 and each passing around a pair of idler sprockets 58. Idler sprockets 58 are spaced apart so that the screw 55 may pass between them. Oneof each pair of idler sprockets is connected to a gear 59, the gears respectively engaging a pair of gears 60 disposed between them and meshing with each other, whereby the two chains 57 are caused to move oppositely in unison. Connection of the idler sprocket 58 to the gear 59 is achieved through a spring urged friction clutch 61 whereby one door may move independently of the other in the event the passage is partially blocked, or both doors may be held against movement while the motor operates in the event the entire passage should be blocked. Each door would be provided with a pressure switch as indicated by switches 47 and 49 in FIG. 6, the switches being connected in parallel whereby either switch may operate the reversible motor.

As so far described, the motor means has been electrical. 'It is to be appreciated that the present invention is readily adapted to the use of piston and cylinder devices operated by air or liquid under pressure. FIGS. 10 and 11 illustrate such a device. It is to be appreciated that a single fluid device would be provided for a single door, and the double device would be provided with the sprocket means of FIG. 7.

In this construction the electric motor would be replaced by a piston and cylinder device comprising a pair of cylinders '74) mounted in the housing 13 and pistons 71 projecting therefrom to which the spring backing members 37 are aflixed. As indicated in FIG. 11, the control circuit, which is essentially the same as that of FIG. 6,

.operatesto actuate a unidirectional motor '72 when either of the pressure switches 47 is closed, and simultaneously to energize the solenoid 73 of a solenoid actuated reversing valve 74. Whenever the motor runs, a pump 75 is actuated to withdraw fluid from a storage chamber 7 6 and direct it through the reversing valve 74. Whenever the solenoid 73 is energized, fluid is passed through the reversing valve to the outer ends of the cylinders 70, thereby withdrawing the spring backing members while one of the doors is being pushed open. When the pressure switch is released the relay 50 completes the circuit to the motor but the solenoid 73 is de-energized to permit the reversing .valve to return to its normal position, thereby directing fluid to the inner ends of the cylinders and causing the backing members to follow the springs as the doors return to their normal positions.

Having illustrated and described preferred embodiments ofthe present invention, it will be appreciated by those skilled in the art that the same permits of other modifications in arrangement and detail. I claim as my invention all such modifications as come within the true spirit and scope of the following claims.

I claim: I

1. A swinging door construction comprising a 'vertical pivot member fixed to the door,

crank means fixed to said pivot member,

a housing disposed above the door and enclosing said crank means,

horizontal guide means in said housing, I

a carriage guided by said guide means for reciprocating movement toward and away from said pivot member,

a helical spring having its axis parallel to the direction of movement of said carriage,

said spring thrusting said carriage against said crank means,

said carriage tending to compress said spring upon being moved away from said pivot member by said crank means when the door is being opened by pressure thereagainst,

a spring backing member against which said spring is compressed,

reversible motor means for moving said backing member toward and away from said pivot member,

and a control circuit for said motor means including a pressure switch,

and means controlled by said pressure switch to cause said motor means to back said backing member away from said pivot member when said pressure switch is closed whereby the compression of said spring is relieved during opening movement of the door and to cause said motor means to move said backing member toward said pivot member when said pressure switch is opened whereby the compression of said spring is re-established during closing movement of the door.

2. The structure set forth in claim 1 wherein said pressure switch comprises a switch operating member mounted upon the door whereby the force applied to close said pressure switch and hold it closed also moves the door open against the pressure of said spring.

3. A swinging door construction comprising a vertical pivot member fixed to the door,

crank means fixed to said pivot member,

a housing disposed above the door and enclosing said crank means,

horizontal guide means in said housing,

a carriage guided by said guide means for reciprocating movement toward and away from said pivot member,

a helical spring having its axis parallel to the direction of movement of said carriage,

said spring thrusting said carriage against said crank means,

said carriage tending to compress said spring upon being moved away from said pivot member by said crank means when the door is being opened by pressure thereagainst,

a spring backing member against which said spring is compressed,

reversible motor means for moving said backing member toward and away from said pivot member,

and a control circuit for said motor means including a pressure switch,

means controlled by said pressure switch to cause said motor means to back said backing member away from said pivot member when said pressure switch is closed whereby the compression of said spring is relieved during opening movement of the door and to cause said motor means to move said backing member toward said pivot member when said pressure switch is opened whereby the compression of said spring is re-established during closing movement of the door,

and a pair of limit switches engageable by said backing member at its limits of movement for arresting said motor means when the door is fully opened or fully closed.

4. The structure set forth in claim 3 wherein said pressure switch comprises a switch operating member mounted upon the door whereby the force applied to close said pressure switch and hold it closed also moves the door open against the pressure of said spring.

5. The construction set forth in claim 3 wherein the one of said limit switches closest to said pivot member is adjustable toward and away from said pivot member whereby to adjust the compressive force of said spring tending to hold the door in closed position.

6. A swinging door construction comprising a vertical pivot member fixed to the door,

crank means fixed to said pivot member and comprising a pair of cranks respectively disposed on opposite sides of the axis of said pivot member,

a housing disposed above the door and enclosing said crank means,

horizontal guide means in said housing,

a carriage guided by said guide means for reciprocating movement toward and away from said pivot memher,

a helical spring having its axis parallel to the direction of movement of said carriage,

said spring thrusting said carriage against said crank means,

said carriage tending to compress said spring upon being moved away from said pivot member by either of said cranks when the door is being opened by pressure thereagainst,

a spring backing member against which said spring is compressed,

reversible motor means for moving said backing member toward and away from said pivot member,

and a control circuit for said motor means including a pressure switch,

means controlled by said pressure switch to cause said motor means to back said backing member away from said pivot member when said pressure switch is closed whereby the compression of said spring is relieved during opening movement of the door and to cause said motor means to move said backing member toward said pivot member when said pressure switch is opened whereby the compression of said spring is re-established during closing movement of the door,

and a pair of limit switches engageable by said backing member at its limits of movement for arresting said motor means when the door is fully opened or fully closed.

7. The structure set forth in claim 6 wherein said pressure switch comprises a switch operating member mounted upon the door whereby the force applied to close said pressure switch and hold it closed also moves the door open against the pressure of said spring.

8. A swinging door construction comprising a vertical pivot member fixed to the door,

crank means fixed to said pivot member,

a housing disposed above the door and enclosing said crank means,

horizontal guide means in said housing,

a carriage guided by said guide means for reciprocating movement toward and away from said pivot member,

a helical spring having its axis parallel to the direction of movement of said carriage,

said spring thrusting said carriage against said crank means,

said carriage tending to compress said spring upon being moved away from said pivot member by said crank means when the door is being opened by pressure thereagainst,

a spring backing follower nut against which said spring is compressed,

a reversible electric motor,

a screw carrying said nut and driven by said motor for moving said nut toward and away from said pivot member,

and a control circuit for said motor including a pressure switch,

means controlled by said pressure switch to cause said motor to rotate in one direction for backing said nut away from said pivot member when said pressure switch is closed whereby the compression of said switch is relieved during opening movement of the door and to cause said motor to rotate in the opposite direction for moving said nut toward said pivot member when said pressure switch is opened whereby the compression of said spring is re-established during closing movement of the door,

and a pair of limit switches engageable by said nut at its limits of movement for arresting said motor when the door is fully opened or fully closed.

9. A swinging door construction comprising a vertical pivot member fixed to the door,

crank means fixed to said pivot member,

a housing disposed above the door and enclosing said crank means,

horizontal guide means in said housing,

a carriage guided by said guide means for reciprocating movement toward and away from said pivot member,

a helical spring having its axis parallel to the direction of movement of said carriage,

said spring thrusting said carriage against said crank means,

said carriage tending to compress said spring upon being moved away from said pivot member by said crank means when the door is being opened by pressure thereagainst,

a spring backing member against which said spring is compressed,

reversible motor means for moving said backing member toward and away from said pivot member comprising a double-acting piston and cylinder device,

an electric motor,

a pump driven by said motor,

and fluid connections between said pump and said device including a reversing valve,

and a control circuit for said motor means including a pressure switch,

means controlled by said pressure switch to operate said motor and said valve to cause said device to back said backing member away from said pivot member when said pressure switch is closed whereby the compression of said spring is relieved during opening movement of the door and to operate said motor and said valve to cause said device to move said backing member toward said pivot member when said pressure switch is opened whereby the compression of said spring is re-established during closing movement of the door,

and a pair of limit switches engageable by said backing member at its limits of movement for arresting said motor when the door is fully opened or fully closed.

10. The structure set forth in claim 9 wherein said pressure switch comprises a switch operating member mounted ,upon the door whereby the force applied to close said pressure switch and hold it closed also moves the door open against the pressure of said spring.

11. A double swinging door construction comprising a pair of oppositely hinged doors,

a pair of vertical pivot members respectively fixed to each of the doors,

a pair of crank means respectively fixed to each of said pivot members,

a housing disposed above the door and enclosing said crank means,

horizontal guide means in said housing,

a pair of carriages guided by said guide means for re ciprocating movements simultaneously in opposite directions toward and away from the respectively adjacent pivot members,

a pair of helical springs having their axes parallel to the direction of movement of said carriages,

said springs respectively thrusting said carriages against the respectively adjacent crank means,

said carriages tending to compress said springs upon being moved away from said respectively adjacent pivot members by said crank means when the doors are being opened,

a pair of spring backing members against which said springs are respectively compressed,

a reversible electric motor for moving said backing members toward and away from the respective pivot members simultaneously and in opposite directions,

and a controlcircuit for said motor including a pressure switch,

means controlled by said pressure switch to cause said motor to back said backing members away from the respective pivot members when said pressure switch is closed whereby the compression of said springs is relieved during opening movement of the doors and to cause said motor to move said backing members toward the respectively adjacent pivot members when said pressure switch is opened whereby the compression of said springs is re-established during closing movement of the doors,

a pair of limit switches associated with each of said backing members and engageable respectively thereby at its limits of movement for arresting said motor when the doors are fully opened or fully closed,

and sprocket chain connecting means between said pivot members for causing simultaneous swinging movements of said doors.

12. The constiuction set forth in claim 11 wherein said sprocket chain means includes friction clutch means for preventing damage to said construction in the event either or both of said doors is prevented from moving to fully opened 'or fully closed position.

13. A double swinging door construction comprising a pair of oppositely hinged doors,

a pair of vertical pivot members respectively fixed to each of the doors,

a pair of crank means respectively fixed to each of said pivot members,

a housing disposed above the door and enclosing said crank means,

horizontal guide means in said housing,

a pair of carriages guided by said guide means for reciprocating movements simultaneously in opposite directions. toward and away from the respectively adjacent pivot members,

a pair of helical springs having their axes parallel to the direction of movement of said carriages,

said springs respectively thrusting said carriages against the respectively adjacent crank means,

said carriages tending to compress said springs upon being moved away from said respectively adjacent pivot members by said crank means when the doors are being opened,

a pair of spring backing members against which said springs are respectively compressed,

a reversible electric motor for moving said backing members toward and away from the respective pivot members simultaneously and in opposite directions,

and a control circuit for said motor including a pair of pressure switches respectively mounted upon said doors and connected in parallel,

means controlled by said pressure switches to cause said motor to back said backing members away from the respective pivot members when either of said pressure switches is closed whereby the compression of said springs is relieved during opening movement of the doors and to cause said motor to move said backing members toward the respectively adjacent pivot members when both of said pressure switches are opened whereby the compression of said springs is re-established during closing movement of the doors,

a pair of limit switches associated with each of said backing members and engageable respectively thereby at its limits of movement for arresting said motor when the doors are fully opened or fully closed,

and sprocket chain connecting means between said pivot members for causing simultaneous swinging movements of said doors.

14. The construction set forth in claim 13 wherein said sprocket chain means include friction clutch means for preventing damage to said construction in the event either or both of said doors is prevented from moving to fully opened or fully closed position.

15. In a swinging door construction including a door pivotalon a predetermined vertical axis between a closed position and an open position, the improvement comprismg a member connected to the door eccentrically of said axis and movable along a predetermined path by the door when the door is moved,

variable spring means normaly urging the member in a door-closing direction with a predetermined force and permitting movement of the member against the action of the spring means as the door is opened,

manually operable means on the door for opening the door,

power means for adjusting the variable spring means to vary the force of the spring means,

and means operable by the manually operable means when actuated to open the door to actuate the power means to adjust the spring means to reduce the resistance of the spring means to opening movement of the door and operable when the manually operable means is released to actuate the power means to adjust the spring means to increase said resistance.

16. In a swinging door construction, including a door pivotal on a predetermined vertical axis between a closed position and an open position, the improvement comprising a member connected to the door eccentrically of said 9 1% axis and movable along a predetermined path by the position and an open position, the improvement comprisdoor when the door is moved, ing variable resilient means normally urging the member in variable resilient means urging the door toward a closed a door-closing direction with a predetermined force position with a predetermined force when in one conand permitting movement of the member against the 5 dition of adjustment and the door is closed, action of the resilient means as the door is opened, movable abutment means controlling the force of the power means for adjusting the variable resilient means resilient means,

to vary the force of the spring means, and power means operable as the door is opened manumanually operable means on the door for opening the ally to move the abutment means in a direction dedoor, 10 creasing the force of the resilient means and operable and control means operable by the manually operable when the door is released to move the abutment means to actuate the power means to adjust the remeans in a direction increasing the force of the resilient means in a direction lessening the force thereof silient means to said predetermined force. tending to close the door as the manually operable means is actuated to move the door in an opening di- 5 References Cited in the file Of this Patent rection and operable by the manually operable means UNITED STATES PATENTS to actuate the power means to adjust the resilient means to increase the force thereof tending to close g 3 3 the door when the manually operable means is not 06mg et a ay actuated and the door is not closed. 20 FOREIGN PATENTS 17. In a swinging door constructron including a door 524,523 Great Britain Aug 8 1940 pivotal on a predetermined vertical axis between a closed 

17. IN A SWINGING DOOR CONSTRUCTION INCLUDING A DOOR PIVOTAL ON A PREDETERMINED VERTICAL AXIS BETWEEN A CLOSED POSITION AND AN OPEN POSITION, THE IMPROVEMENT COMPRISING VARIABLE RESILIENT MEANS URGING THE DOOR TOWARD A CLOSED POSITION WITH A PREDETERMINED FORCE WHEN IN ONE CONDITION OF ADJUSTMENT AND THE DOOR IS CLOSED, MOVABLE ABUTMENT MEANS CONTROLLING THE FORCE OF THE RESILIENT MEANS, AND POWER MEANS OPERABLE AS THE DOOR IS OPENED MANUALLY TO MOVE THE ABUTMENT MEANS IN A DIRECTION DECREASING THE FORCE OF THE RESILIENT MEANS AND OPERABLE WHEN THE DOOR IS RELEASED TO MOVE THE ABUTMENT MEANS IN A DIRECTION INCREASING THE FORCE OF THE RESILIENT MEANS TO SAID PREDETERMINED FORCE. 